In recent years, electric appliances, which are capable of receiving power in a contactless manner with high efficiency, have become practical (for example, Patent Document 1). For example, a primary coil of a contactless power supplying device is embedded in a flat structure such as a desk. When an electric appliance including a secondary coil is placed on the primary coil, the electric appliance can receive power. Further, by using a contactless adaptor including a secondary coil, the electric appliance can receive power through a connecting wire.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-151900